Blood Vessels. Structure and Function Quiz

Continuous capillaries have tight junctions between endothelial cells, while fenestrated capillaries have small pores or fenestrations.

Sinusoids are found in the liver, spleen, bone marrow, and adrenal glands, allowing for the transport of large substances including formed elements and plasma proteins.

Intercellular clefts in continuous capillaries prevent the movement of large substances but allow small substances and fluids to pass through by diffusion and bulk flow.

<p>Capillary beds facilitate the exchange of oxygen, nutrients, and waste materials between blood and tissues.</p> Signup and view all the answers

<p>At any given time, only about one-quarter of capillary beds are open due to the vast number of capillaries and limited blood volume.</p> Signup and view all the answers

<p>The BBB is formed by modified continuous capillaries with thickened basement membranes and no intercellular clefts, restricting substance passage.</p> Signup and view all the answers

<p>Fenestrated capillaries allow the movement of small substances through pores, whereas sinusoids have large openings that permit the transport of large substances, including formed elements.</p> Signup and view all the answers

<p>Only nonpolar molecules and specific regulated substances can pass through the endothelial cells of the BBB.</p> Signup and view all the answers

<p>Precapillary sphincters regulate the blood flow by relaxing or contracting.</p> Signup and view all the answers

<p>True arterial end capillaries have a continuous layer of endothelium and smooth muscle cells, while venous end capillaries have a discontinuous layer of endothelium and no smooth muscle cells.</p> Signup and view all the answers

<p>The thoroughfare channel allows blood to bypass the capillary bed and flow directly into the postcapillary venule.</p> Signup and view all the answers

<p>Hydrostatic pressure is the force exerted by a fluid against the walls of its container, while colloid osmotic pressure is the force exerted by proteins and large molecules pulling water into a solution.</p> Signup and view all the answers

<p>Vasomotion refers to the rhythmic contraction and relaxation of capillaries occurring at 5 to 10 cycles per minute.</p> Signup and view all the answers

<p>Slower blood flow in capillaries enhances the exchange of gases, nutrients, and wastes by allowing more time for diffusion.</p> Signup and view all the answers

<p>A simple pathway includes one major artery, branching into smaller arteries, arterioles, a single capillary bed, followed by a venule and major vein.</p> Signup and view all the answers

<p>Anastomoses are the junctions of two or more blood vessels that provide alternative pathways for blood supply.</p> Signup and view all the answers

<p>The formula for calculating NFP is NFP = (HPb - HPi) - (COPb - COPi).</p> Signup and view all the answers

<p>A positive NFP value indicates that hydrostatic pressure is greater than colloid osmotic pressure, leading to filtration of fluid out of the capillary.</p> Signup and view all the answers

<p>Veins can store blood, allowing it to be shifted back into circulation through vasoconstriction when needed.</p> Signup and view all the answers

<p>COP helps to draw fluid back into the blood vessels due to the presence of proteins, thus opposing hydrostatic pressure.</p> Signup and view all the answers

<p>Blood flow velocity is inversely related to the total cross-sectional area of the vessels.</p> Signup and view all the answers

<p>NFP is positive at the arterial end, promoting filtration, while it becomes negative at the venous end, indicating reabsorption.</p> Signup and view all the answers

<p>Filtration is the movement of fluid out of the capillaries, while reabsorption is the return of fluid back into the bloodstream.</p> Signup and view all the answers

<p>Angiogenesis, the formation of new blood vessels, enhances capillary density, improving oxygen and nutrient delivery to tissues.</p> Signup and view all the answers

<p>Valves in veins prevent the backflow of blood, ensuring it flows toward the heart.</p> Signup and view all the answers

<p>The direction of fluid movement is primarily influenced by the balance between hydrostatic pressure and colloid osmotic pressure.</p> Signup and view all the answers

<p>Veins consist of tunica intima, tunica media, and tunica adventitia.</p> Signup and view all the answers

<p>A portal system involves blood flowing through two capillary beds in series, unlike a simple pathway with only one capillary bed.</p> Signup and view all the answers

<p>The types of transport include diffusion, vesicular transport, and bulk flow.</p> Signup and view all the answers

<p>Continuous capillaries are least permeable, fenestrated capillaries allow for substance exchange, and sinusoid capillaries are the most permeable.</p> Signup and view all the answers

<p>The anatomic structure of capillaries, such as fenestrations, facilitates the passage of larger solutes between blood and tissues.</p> Signup and view all the answers

<p>The tunica externa provides structural support and contains the vasa vasorum, which supplies blood to the vessel walls.</p> Signup and view all the answers

<p>Slow blood flow in capillaries allows sufficient time for the exchange of oxygen, nutrients, and waste products.</p> Signup and view all the answers

<p>Hydrostatic pressure promotes the filtration of fluids from capillaries into the surrounding tissues.</p> Signup and view all the answers

<p>Proteins such as albumin contribute to blood colloid osmotic pressure by attracting water into the bloodstream.</p> Signup and view all the answers

<p>Increased tissue hydrostatic pressure can lower NFP, potentially decreasing filtration and promoting reabsorption.</p> Signup and view all the answers

<p>The blood pressure gradient is caused by the heart's rhythmic contractions, leading to higher pressure in the arteries and lower pressure in the veins.</p> Signup and view all the answers

<p>Pulse pressure is calculated as the difference between systolic and diastolic pressure and indicates the elasticity and recoil of the arteries.</p> Signup and view all the answers

<p>Persistently high pulse pressure is a risk factor for cardiovascular disease and indicates increased cardiovascular workload.</p> Signup and view all the answers

<p>Mean arterial pressure (MAP) is the average arterial pressure during a cardiac cycle, calculated as MAP = diastolic pressure + 1/3 pulse pressure.</p> Signup and view all the answers

<p>Venous blood pressure is not pulsatile, averaging about 20 mm Hg, and is crucial for the venous return of blood to the heart.</p> Signup and view all the answers

<p>Skeletal muscle pumps help propel blood within the veins of the limbs by compressing the veins during muscle contraction.</p> Signup and view all the answers

<p>Common pulse points include the carotid, radial, and femoral arteries, and they are crucial for assessing heart rate and circulation.</p> Signup and view all the answers

<p>The absence of a pulse can indicate life-threatening conditions such as cardiac arrest or severe hypovolemia.</p> Signup and view all the answers

<p>The heart, through its pumping action, establishes the blood pressure gradient.</p> Signup and view all the answers

<p>The skeletal muscle pump and the respiratory pump help overcome the small pressure gradient in veins.</p> Signup and view all the answers

<p>Capillary blood pressure must be sufficient for filtration and reabsorption of substances while avoiding capillary damage.</p> Signup and view all the answers

<p>Varicose veins are dilated and tortuous veins caused by genetic predisposition, aging, or prolonged stress on the veins.</p> Signup and view all the answers

<p>Circulatory shock is a state of insufficient blood flow for tissue perfusion, which can be caused by decreased blood volume.</p> Signup and view all the answers

<p>DVT can lead to complications such as pulmonary embolism, which may cause respiratory failure or death if a clot travels to the lungs.</p> Signup and view all the answers

<p>Resistance opposes blood flow, making blood flow inversely related to resistance.</p> Signup and view all the answers

<p>Increased metabolic activity leads to vasodilation, reducing resistance and affecting blood pressure dynamics.</p> Signup and view all the answers

<p>Higher blood viscosity increases resistance to flow, while lower viscosity decreases it.</p> Signup and view all the answers

<p>Mean arterial pressure is the average blood pressure during a single cardiac cycle, important for assessing cardiovascular health.</p> Signup and view all the answers

<p>As vessels age or become diseased, they lose elasticity, resulting in diminished pulse pressure and increased difficulty for the heart to pump blood.</p> Signup and view all the answers

<p>Capillary blood pressure drives the exchange of nutrients and waste between blood and tissues.</p> Signup and view all the answers

<p>Blood flow is directly proportional to the fourth power of the vessel radius, while a smaller radius increases resistance.</p> Signup and view all the answers

<p>Decreased cardiac output or vasodilation can lead to a decrease in mean arterial pressure.</p> Signup and view all the answers

<p>Laminar flow is the blood flow in parallel layers with minimal mixing, making it efficient as it reduces friction and turbulence.</p> Signup and view all the answers

<p>Atherosclerosis can cause narrowing of blood vessels, increasing resistance and decreasing blood flow.</p> Signup and view all the answers

<p>Obstructed veins, extended immobility, and extensive vasodilation can all contribute to circulatory shock.</p> Signup and view all the answers

<p>Increased cardiac output raises the pressure gradient, enhancing blood flow throughout the body.</p> Signup and view all the answers

<p>The skeletal muscle pump is important as it aids in moving blood back to the heart against gravity from the lower limbs.</p> Signup and view all the answers

<p>The three main layers are the tunica intima, tunica media, and tunica externa.</p> Signup and view all the answers

<p>The tunica media in arteries is thicker and contains more elastic fibers than in veins.</p> Signup and view all the answers

<p>Capillaries consist solely of the tunica intima, which allows for rapid gas and nutrient exchange.</p> Signup and view all the answers

<p>The vasa vasorum supplies blood to the tunica externa of large blood vessels.</p> Signup and view all the answers

<p>Atherosclerosis leads to thickening and narrowing of the arterial lumen due to plaque buildup.</p> Signup and view all the answers

<p>The three types are elastic arteries with high elastic fiber content, muscular arteries with more smooth muscle, and arterioles with a few layers of smooth muscle cells.</p> Signup and view all the answers

<p>Vasomotor tone allows for slight contraction of smooth muscle in arterioles, regulating blood flow and blood pressure.</p> Signup and view all the answers

<p>Companion vessels are paired arteries and veins that supply the same body region.</p> Signup and view all the answers

<p>Elastic arteries stretch to accommodate blood during ventricular systole and recoil to help propel blood during diastole.</p> Signup and view all the answers

<p>Valves in veins prevent the backflow of blood as it returns to the heart.</p> Signup and view all the answers

<p>Angiogenesis in skeletal muscle during aerobic training enhances blood flow and oxygen delivery by forming new blood vessels, which supports increased metabolic demands over time.</p> Signup and view all the answers

<p>The tunica wall composition changes as arteries branch, gradually allowing less elastic and more smooth muscle as they become arterioles.</p> Signup and view all the answers

<p>Inadequate perfusion leads to decreased oxygen and nutrient levels, promoting the metabolic activity of cancerous cells and enhancing their growth due to elevated local vasodilators.</p> Signup and view all the answers

<p>Autoregulation of blood flow is the ability of tissues to maintain consistent blood flow despite changes in systemic blood pressure, achieved through myogenic, metabolic, and neurogenic responses.</p> Signup and view all the answers

<p>Hypercholesterolemia is a risk factor that promotes plaque buildup, leading to narrowed arteries.</p> Signup and view all the answers

<p>An aneurysm is a ballooning of part of the arterial wall, which can rupture and cause massive bleeding.</p> Signup and view all the answers

<p>Reactive hyperemia is the increase in local blood flow following a period of ischemia, resulting in the stretching of blood vessel smooth muscle and subsequent vasoconstriction to maintain blood flow.</p> Signup and view all the answers

<p>Vasodilators relax smooth muscle in blood vessel walls, increasing blood flow, while vasoconstrictors contract the muscle, reducing blood flow.</p> Signup and view all the answers

<p>The blood pressure gradient is essential for facilitating blood flow through the cardiovascular system, with the gradient providing the driving force for blood returning to the heart.</p> Signup and view all the answers

<p>Total blood flow is determined by blood pressure and vascular resistance, and it directly increases with higher cardiac output, providing more blood to tissues.</p> Signup and view all the answers

<p>Histamine and bradykinin promote vasodilation during inflammation by stimulating arterioles directly or inducing nitric oxide release from endothelial cells.</p> Signup and view all the answers

<p>Local factors such as metabolic activity and the release of vasoactive substances adjust blood flow by causing vasodilation or vasoconstriction in response to tissue needs.</p> Signup and view all the answers

<p>Mean arterial pressure (MAP) is the average pressure in a person's arteries during one cardiac cycle, and it is crucial for ensuring sufficient blood flow to organs.</p> Signup and view all the answers

<p>They constrict in response to norepinephrine.</p> Signup and view all the answers

<p>Baroreceptor reflexes, which maintain blood pressure through negative feedback.</p> Signup and view all the answers

<p>They help restore normal blood chemistry by reacting to high carbon dioxide levels, low pH, and low oxygen levels.</p> Signup and view all the answers

<p>It increases heart rate and stroke volume.</p> Signup and view all the answers

<p>The vasomotor center increases signals for vasoconstriction, thereby increasing peripheral resistance.</p> Signup and view all the answers

<p>The cardioinhibitory system increases nerve signals to the heart.</p> Signup and view all the answers

<p>The aortic bodies and carotid body; they detect changes in blood chemistry.</p> Signup and view all the answers

<p>They detect changes in blood pressure and adjust nerve signals to the heart and blood vessels.</p> Signup and view all the answers

<p>Blood flow lessens.</p> Signup and view all the answers

<p>Increased blood viscosity, blood vessel length, or decreased vessel lumen diameter.</p> Signup and view all the answers

<p>It leads to elevated arterial blood pressure readings.</p> Signup and view all the answers

<p>They adjust blood pressure and blood flow as needed to maintain adequate tissue perfusion.</p> Signup and view all the answers

<p>The heart, blood vessels, and components of the nervous system.</p> Signup and view all the answers

<p>They monitor blood pressure changes by detecting stretch in the blood vessel walls.</p> Signup and view all the answers

<p>It increases peripheral resistance due to vasoconstriction of blood vessels.</p> Signup and view all the answers

<p>It regulates blood pressure through a negative feedback loop by adjusting cardiac output and peripheral resistance.</p> Signup and view all the answers

<p>The cardiac center regulates heart activity while the vasomotor center adjusts blood vessel constriction.</p> Signup and view all the answers

<p>There is an increase in circulating blood volume due to vasoconstriction of veins.</p> Signup and view all the answers

<p>They decrease heart rate, resulting in smaller cardiac output.</p> Signup and view all the answers

<p>Their response varies between vasoconstriction and vasodilation based on receptor subtypes.</p> Signup and view all the answers

<p>Changes in the stretch of the blood vessel wall activate baroreceptors.</p> Signup and view all the answers

<p>They regulate heart rate, stroke volume, and blood pressure dynamically.</p> Signup and view all the answers

<p>Veins carry blood towards the heart.</p> Signup and view all the answers

<p>Superior vena cava and inferior vena cava.</p> Signup and view all the answers

<p>The internal carotid artery branches into the anterior and middle cerebral arteries.</p> Signup and view all the answers

<p>The circle of Willis equalizes blood pressure in the brain and provides alternative blood delivery routes.</p> Signup and view all the answers

<p>External jugular veins, anterior jugular veins, and facial veins.</p> Signup and view all the answers

<p>They supply blood to various regions of the head and neck, including the thyroid and face.</p> Signup and view all the answers

<p>The external jugular veins.</p> Signup and view all the answers

<p>Posterior cerebral arteries and posterior communicating arteries.</p> Signup and view all the answers

<p>It can lead to fluid remaining in the interstitial fluid, potentially causing edema.</p> Signup and view all the answers

<p>Total blood flow decreases due to increased resistance, despite constant cardiac output.</p> Signup and view all the answers

<p>Baroreceptors detect decreased stretch in the carotid artery and initiate a reflex to increase blood flow to the brain.</p> Signup and view all the answers

<p>Epinephrine.</p> Signup and view all the answers

<p>The tunica media in arteries is thicker, allowing for greater contractile strength and higher blood pressure.</p> Signup and view all the answers

<p>Losing weight reduces compressive forces on thoracic organs, decreasing resistance and, consequently, blood pressure.</p> Signup and view all the answers

<p>Blood flow velocity is slowest in veins, facilitating nutrient and gas exchange at the capillary level.</p> Signup and view all the answers

<p>Hydrostatic pressure decreases in the blood, causing fluid to remain in circulation when colloid osmotic pressure increases.</p> Signup and view all the answers

<p>Baroreceptors increase nerve signals to blood vessels when they detect decreased blood pressure, resulting in vasoconstriction.</p> Signup and view all the answers

<p>Hormones such as angiotensin II and aldosterone are involved in raising blood pressure.</p> Signup and view all the answers

<p>The renin-angiotensin system raises blood pressure by producing angiotensin II, which acts as a potent vasoconstrictor.</p> Signup and view all the answers

<p>Nicotine increases blood pressure by stimulating the SA node and causing arteriole vasoconstriction.</p> Signup and view all the answers

<p>ANP lowers blood pressure by promoting vasodilation and increasing urine output.</p> Signup and view all the answers

<p>Aldosterone increases blood pressure by enhancing sodium and water absorption in the kidneys.</p> Signup and view all the answers

<p>Systolic pressure is the pressure in the arteries when the heart ventricles contract, measured when the first pulsating sound is heard.</p> Signup and view all the answers

<p>Increased peripheral resistance leads to higher blood pressure and reduced blood flow.</p> Signup and view all the answers

<p>Blood pressure in pulmonary circulation is significantly lower than in systemic circulation.</p> Signup and view all the answers

<p>During exercise, total blood flow increases, particularly to skeletal muscles and the heart.</p> Signup and view all the answers

<p>ADH increases blood pressure by promoting water reabsorption and decreasing urine output.</p> Signup and view all the answers

<p>Cardiac output, resistance, and blood volume all directly influence blood pressure: increasing any variable raises blood pressure.</p> Signup and view all the answers

<p>The branches of the aortic arch supply essential blood to the head, neck, and upper limbs.</p> Signup and view all the answers

<p>Vasodilation decreases peripheral resistance, leading to lower blood pressure.</p> Signup and view all the answers

<p>Measuring blood pressure is critical to diagnose conditions like hypertension and monitor cardiovascular health.</p> Signup and view all the answers

<p>The two main branches are the internal carotid artery, which supplies the brain, and the external carotid artery, which supplies the face and neck.</p> Signup and view all the answers

<p>The three arteries are the celiac trunk, superior mesenteric artery, and inferior mesenteric artery.</p> Signup and view all the answers

<p>Dural venous sinuses drain blood from the brain and receive cerebrospinal fluid, which is not typical for regular veins.</p> Signup and view all the answers

<p>The hepatic portal system transports venous blood from the gastrointestinal tract to the liver for processing before it enters systemic circulation.</p> Signup and view all the answers

<p>The umbilical vein carries oxygenated blood from the placenta to the fetus.</p> Signup and view all the answers

<p>After birth, the ductus arteriosus closes and becomes the ligamentum arteriosum, allowing normal pulmonary circulation to begin.</p> Signup and view all the answers

<p>The great saphenous vein is longer and located medially, while the small saphenous vein is shorter and located posteriorly.</p> Signup and view all the answers

<p>Anastomoses provide alternative pathways for blood flow, ensuring continuous circulation even if one vessel is blocked.</p> Signup and view all the answers

<p>The azygos vein drains blood from the right side of the thoracic wall and receives blood from the hemiazygos vein.</p> Signup and view all the answers

<p>The kidneys are supplied by the renal arteries, and the adrenal glands are supplied by the adrenal arteries.</p> Signup and view all the answers

<p>Fetal structures like the ductus venosus and foramen ovale close, adapting circulation for postnatal life.</p> Signup and view all the answers

<p>The internal thoracic artery supplies blood to the anterior chest wall and has branches like the anterior intercostal arteries.</p> Signup and view all the answers

<p>Blood flow slows in capillaries to allow efficient nutrient and gas exchange.</p> Signup and view all the answers